Lifting devices for elevating stacked articles employing a support member inserted beneath the articles to be lifted, as, for example, using forklifts for elevating palletized loads, are well known and have been heretofore suggested and/or utilized. Additional examples of stacked article lifting devices can be found in U.S. Pat. Nos. 3,522,890, 3,643,822, and 3,884,366.
Devices for elevation of a single layer of articles employing vacuum cups, magnetic heads and the like are also well known and such devices have heretofore been suggested and/or utilized for the arrangement of articles into desired loads (see, for example, U.S. Pat. Nos: 4,242,025, 3,780,884, 3,757,966, 4,252,497, 4,566,836, 3,859,772, 3,836,017, 3,544,410, 3,682,290, and 3,300,065.
Various palletizing and depalletizing devices employing push cylinders, bulkheads, clamps and/or tilting mechanisms have also been heretofore suggested and/or utilized for removal of articles from, and/or placement of articles on, pallets and the like.
While such devices now known have been found to be acceptable for some uses, such devices have not been found to be capable of and/or suitable for suspending multiple layers, or tiers, of stacked articles relative to a reference surface without the necessity of providing a supporting member at the bottom surface of the suspended load or high clamping forces to the load. Moreover, no such known devices have been capable of establishing a pressure differential to effect suspending, or lifting, of selected plural tiers of articles.